Load sensing system

ABSTRACT

A load sensing system for maximizing the cleaning efficiency of particulate raw materials such as sand, gravel, rock, ores, etc. in a log washer by sensing the weight of the aggregate in the log washer tank and adjusting the angle of inclination of the tank for cleaning efficiency. The system includes a log washer tank pivoted at its lower end and supported by hydraulic cylinders at its upper end. A high/low pressure sensor detects changes in the weight of the load by changes in hydraulic fluid pressure, and raises or lowers the upper end of the tank when low or high pressure limits are exceeded through solenoid activated hydraulic valves.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to aggregate materialcleaning systems. More specifically, the invention is a fully automatic,load sensing system for a log washer which is used for cleaningaggregate materials, such as rocks, gravel, sand, and ores to removedirt and waste materials. The system hydraulically changes the angle ofincline of the washer tank to ensure that the washer tank is properlyloaded with the solids for efficient cleaning action.

[0003] 2. Description of the Related Art

[0004] The related art of interest describes various washing andweighing apparatus, but none recognizes the washing inefficiency problemand none discloses the present invention. There is a need for a logwasher for washing sand, gravel, ores, and similar particulate materialto maximize the cleaning action based upon variations in the weight ofthe load being cleaned. The problem exists because in conventional logwashers the inclination angle of the washer tank is fixed, whereas theload fluctuates. As a general rule, if the angle of incline of the tankis increased, production is decreased but the cleansing action of thewasher is increased. Conversely, if the angle of incline of the washeris decreased, production is increased, but the cleansing action isdecreased. Currently, the only way to vary the angle of incline is bymanually increasing or decreasing the height of the structure supportingthe washer tank, a labor intensive process which involves temporarilyshutting down the log washer while the supports are adjusted. Therefore,by automatically adjusting the incline of the washer tank according tothe load of solids, adequate cleaning is accomplished to maximize theefficiency of the washing process. The related art will be discussed inthe order of perceived relevance to the present invention. No artdiscloses the critical feature of automatically adjusting the incline ofthe washer or separator tank to adjust to the weight of the solids loadin the washer.

[0005] U.S. Pat. No. 3,807,558 issued on Apr. 30, 1974, to Alton B. Hammdescribes an apparatus for separating lightweight debris from sand,gravel and logs comprising flowing water at a high velocity in arestricted flow path to one side of the rotating auger and rotatinglogs. The granular and aggregate material is discharged into the waterflow for removing unwanted lightweight debris prior to the movement ofthe granular and material into the zone of operation of the auger of thesand screw or rotating logs of the log washer. The apparatus'sinclination is supported by fixed supports. The apparatus isdistinguishable for requiring a restricted water flow path and fixedsupports for its inclination angle.

[0006] Japan Patent Application No. 7-253340 published on Oct. 3, 1995,describes an apparatus which can automatically perform an aggregatewashing step in a pivotal mixing container with a spout and emptying theaggregate material and liquid. The washer apparatus has a pair ofsupporting legs on a stage, and a base pad that may be rotated via apivotal shaft in a vertical direction by the supporting legs to emptythe contents. The aggregate mixing container has a mixing blade withinrotated by a first drive motor which rotates with the container. Thesecond drive motor rotates the mixing container and the first drivemotor. The apparatus is distinguishable for being limited to a rotatableemptying feature for a mixing container.

[0007] U.S. Pat. No. 4,234,415 issued on Nov. 18, 1980, to Enrique deTuya Casuso describes an apparatus for separating mixed solids ofdifferent specific gravities by means of a liquid medium comprising arotatable frusto-conical separation chamber having a lighter solidoutlet at one end and a heavier solid outlet at the opposite end. A pairof frusto-conical chambers may be utilized to separate solids of threedifferent specific gravities. The apparatus is distinguishable for itsstructural difference and its different objective of separating mixedsolids of at least two different specific gravities.

[0008] U.S. Pat. No. 5,868,256 issued on Feb. 9, 1999, to Maynard A.Teppo describes a rotary clay material refiner apparatus comprising ahorizontal rotating drum into which clay material and water are fed. Theclay material and water form a slurry which is agitated by lifterswithin the drum. A series of adjustable lifters within the drum refinethe slurry by lifting aggregates and rocks out of the slurry anddischarging them out of the refiner apparatus. The refined slurry exitsthe drum through an opening and further processed. The apparatus isdistinguishable for being confined to a horizontal rotating drum andrequiring two separation steps.

[0009] U.S. Pat. No. 2,489,161 issued on Nov. 22, 1949, to WilliamScholes describes a gravity liquid separator apparatus for theseparation of unspecified granular or lump material, comprising a tankminus an outlet wall and the bottom inclined up from the deep feedingend, wherein the material is fed from the bottom of the deep end by acontinuous belt passing through an opening with a trailing rubber fabricsealing flap or an inflated pneumatic tube to minimize leakage. A rotaryscraper is positioned midway in the apparatus. The apparatus isdistinguishable for requiring a rotating material transporting beltinside the tank.

[0010] U.S. Pat. No. 2,336,991 issued on Dec. 14, 1943, to Chester I.Leveke describes an apparatus for removing dirt, clay, shale, coal andthe like material from gravel comprising an inclined elongated troughhaving a square cross-section, a substantially open top, a bottom graveloutlet in the forward end and a hopper, and a gravel escape slot at theopposite end. A centered rotating cylindrical agitator having agitatingblades and three portions of decreasing diameter to the outlet. Theapparatus is distinguishable for lacking any inclination adjustablemeans.

[0011] U.S. Pat. No. 1,972,195 issued on Sep. 4, 1934, to Marmaduke J.Lacy, Jr. describes an ore washer apparatus for washing ores such asphosphates, manganese and iron or concrete aggregates containing clay,chips, and silt in a fixed inclined frame. The moving gear comprises 5parallel chains bearing plow share blades rotating on three sprocketwheels to define a triangle as viewed from the side. The ores are addedin the baffled rear end and pushed to the front end in water fordischarge out of the water via a discharge throat. The apparatus isdistinguishable for requiring an immovable fixed tank.

[0012] U.S. Pat. No. 1,695,021 issued on Dec. 11, 1928, to Samuel R.Puryear describes an apparatus for separating solids comprising asubstantially rectangular inclined tank with an enlarged rear end andtwin screws. The solids such as mud balls mixed with gravel, lignite,coal, shale, and shells are fed with water from a chute into the rearend of the tank. The lighter materials are flushed by water jets towardan adjustable wier and into a perforated conduit leading to a reartrough. The twin screws carry the heavier material up the inclined tankout of the water and into a delivery chute. The apparatus isdistinguishable for requiring a rear separation trough and directionaljets of water.

[0013] U.S. Pat. No. 2,025,841 issued on Dec. 31, 1935, to Charles H.Young describes an apparatus for washing gravel to remove shale,lignite, bark, water-logged wood, and coal comprising an inclined tankon a frame support, and having a pair of screw conveyors which acceptthe heavier gravel feed from a shallow pan which discharges the heaviermaterial in the rear. The screw conveyors move the gravel through waterto an outlet. Jets of water are also supplied continuously upwardthrough the mixture from a bottom pipe. The apparatus is distinguishablefor requiring a fixed support.

[0014] U.S. Pat. No. 4,448,678 issued on May 15, 1984, to Cecil C.Gentry describes an apparatus for lignite beneficiation comprising aninclined treatment trough having a two-section conveyor screw consistingof a notched screw in the front and a helical screw. In the rear of thetrough, crushed lignite is fed into a settling pool of water having aweir in the rear wall covering an exiting stream, while above the streamwaste tailings flow over the rear wall. Water is sprayed above thetrough. The lignite product exits at the front portion of the trough.Fixed supports are illustrated to obtain the inclination angle of thetrough. The apparatus is distinguishable for requiring a two-sectionconveyor screw and fixed supports for inclining the trough.

[0015] U.S. Pat. No. 1,609,652 issued on Dec. 7, 1926, to John L.McQueen describes a log washer apparatus comprising twin screws havingintermeshing paddles with cutting edges for washing sand, gravel, ores,and manganese to remove clay, dirt and waste matter. The apparatus isdistinguishable for requiring specific log washer screws.

[0016] U.S. Pat. No. 2,050,458 issued on Aug. 11, 1936, to MelvinOvestrud et al. describes a wheeled apparatus for treating quarried rockor pit run gravel to produce aggregates for concrete construction workcomprising, in sequence, an upper scrubber chamber (inclined downward)receiving the raw feed, a coarse and fine particle conveyor, and adehydrator chamber with an endless conveyor belt. A screen at the end ofscrubber chamber filters the smaller particles which pass down a hopperto a crusher. The apparatus is distinguishable for requiring multipleseparation elements, a crusher, and lacking any adjustment of theinclination of the scrubber chamber.

[0017] U.S. Pat. No. 2,324,549 issued on Jul. 20, 1943, to Paul L.Wigton describes a spiral ore pulp classifier apparatus comprising anupwardly inclined open tank on fixed supports being fed ore pulp intothe tank having pool of water and a spiral conveyor. The pool end of thetank has an upper outlet for slime and a bottom outlet for a drain. Sandis discharged from the front end. The apparatus is distinguishable forrequiring a fixed inclination.

[0018] U.S. Pat. No. 5,992,776 issued on Nov. 30, 1999, to Gianni B.Arcaini et al. describes a process for processing ash from the massburning of municipal waste utilizing various apparatus comprising ashear-force shredder for the size reduction of bulky items, impactcleaning of ferrous metal items, and a rotary washer for cleaningnon-ferrous materials. The ash is sent through an air separation unit toremove, paper, wood, plastic, and other unburned debris before passingthe ash to an eddy current separator for non-ferrous material removal.The ash is free of metals values, unburned materials and unshreddables,but must be treated to immobilize certain heavy metals. The ash isrecycled through a closed loop to increase removal efficiency of themetals and the homogeneous nature of the recovered treated ashaggregate. The apparatus used in this process is distinguishable for notrequiring an inclined separator.

[0019] U.K. Patent Application No. GB 2,280,384, published on Jan. 2,1995, describes a horizontal bucket wheel sand washer with a submergedrecovered fine aggregate transporter apparatus so that its movement doesnot agitate or disturb the flowing water. The submerged transporter maybe a screw conveyor or a multi-bladed scraper mounted on a framereciprocated by rams and guided in elevated return movement over pivotedcams. The apparatus is distinguishable for its required horizontalstructure.

[0020] Japan Patent Application No. 8-168693 published on Jul. 2, 1996,describes an inclined apparatus to prevent fine aggregate such as sandfrom being mixed with the muddy water being carried off by a conveyorbelt, when the fine aggregate such as sand is taken out from a watertank by a belt conveyor device. The silt is collected in a hopper and toa conveyor belt, while the muddy water is collected in a separatecontainer. The apparatus is distinguishable for lacking any change inthe inclination.

[0021] Japan Patent Application No. 9-203407 published on Aug. 5, 1997,describes a screw conveyor and washer apparatus comprising multiplewashers connected in a single line via microjoints. Multiple screws withindividual washers in a single line are attached to a supplying means ofunknown material. Each washer is separated in turn at its microjointpart so that the screw with its washer is supplied. The apparatus isdistinguishable for its required microjointed structure.

[0022] German Patent Application No. DE 19,928,287, published on Dec.28, 2000, describes a method for disposing excavated waste material byconveying the waste material to a buffer container for delivery to adrum washer wherein coarse particles are separated from finer particles,and the overflow is supplied to a hydro-cyclone screen apparatus forrecycle of the fluid and the disposal of the solids to a dump. Theapparatus employed is distinguishable for requiring a drum washer and ahydro-cyclone screen.

[0023] None of the above inventions and patents, taken either singly orin combination, is seen to describe the instant invention as claimed.Thus, a load sensing system to obtain the proper inclination of thewasher tank solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

[0024] The present invention is directed to a load sensing system forlog washers for washing coarse materials, such as rocks, sand, gravel,and ores, in order to improve the washing process in an open inclinedtank. Conventional log washer apparatus are affected by the angle atwhich the washer tank is fixed. If the load in the log washer tankbecomes too light for the angle of incline of the tank, the cleansingaction becomes inadequate. Conventional log washer tanks have noautomated mechanism for automatically adjusting the inclination of thetank in response to changes in the load. The present inventionautomatically changes the angle of incline of the washer apparatus byadding hinges to the lower portion of the tank and hydraulic cylindersto raise and lower the upper portion of the tank in response to changesin pressure caused by the load in the tank.

[0025] In the load sensing system of the present invention, the lowerend of the log washer tank is mounted on a hinged support and the upperend of the tank is supported by a pair of hydraulic cylinders or rams. Ahigh-low pressure sensor device senses changes in the weight of the loadin the tank and activates solenoid switches connected to hydraulicvalves and to an electric motor which activates a hydraulic pump inorder to raise or lower the hydraulic rams as required.

[0026] If the hydraulic pressure is low as read by the high/low pressuresensor, the total weight of the material in the washer tank isconsidered below the optimum weight desired. Therefore, the low pressuresensor switch will activate a hydraulic pump by a starter motor and ahydraulic valve. This action will create the hydraulic flow that flowsthrough a flow divider circuit to a pair of hydraulic cylinders toincrease the incline of the washer tank. The elevated washer tank endwill rise until the load weight increases, or until a high limit switchindicates that maximum extension of the rams is reached. Now, the firsthydraulic valve will close to hold the washer tank position. When theload increases in weight, the high-low pressure sensor will sense thiscondition, and will activate a latching relay device to the tanklowering circuit. The lowering valve is activated to let the hydraulicoil back through the divider combiner valve to the oil tank. Thelowering valve will lower the washer tank as long as the load in thewasher tank is sufficient to activate the high-low pressure sensor.

[0027] If the bottommost incline value is not reached, and the loaddecreases, the low pressure sensor will activate the latching relay inthe raising circuit to raise the inclination angle of the washer tank.If the washer tank load reaches the lowest incline limit, the systemwill operate at the setting of the inclination angle until the lowsensor senses the lower pressure of a light load, and activates thelatching relay in the tank raising circuit. A needle valve regulates howrapidly the tank lowers. A high pressure relief valve diverts or bleedsoff hydraulic oil to return to the oil tank, if the low pressure limitsetting is reached. A check valve is required to ensure that thehydraulic oil does not flow in the opposite direction. Thus, the loadsensing system operates to maximize the washing process for an openinclined tank with conveyor screws.

[0028] Accordingly, it is a principal object of the invention to providea load monitoring system for monitoring the load absent the water in aninclined log washer tank.

[0029] It is another object of the invention to provide a monitoringsystem for monitoring the load in an inclined log washer tank coupled toa mechanism which raises and lowers the angle of inclination of thetank, which maximizes the washing efficiency of the log washer.

[0030] It is a further object of the invention to provide a monitoringsystem for monitoring the load in an inclined washer tank which isresponsive to a high/low pressure sensor connected to a mechanism forraising and lowering the inclination of the tank.

[0031] Still another object of the invention is to provide a monitoringsystem for monitoring the load in a log washer tank which automaticallymaximizes the efficiency of the log washer through a high/low pressuresensor connected to a hydraulic system for changing the inclination ofthe tank in response to changes in the load.

[0032] It is an object of the invention to provide improved elements andarrangements thereof for the purposes described which is inexpensive,dependable and fully effective in accomplishing its intended purposes.

[0033] These and other objects of the present invention will becomereadily apparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIG. 1A is a partial environmental, perspective side view of aportion of the load sensing system applied to the loading of aparticulate washing tank according to the present invention.

[0035]FIG. 1B is an enlarged perspective view of the FIG. 1 portion ofthe load sensing system applied to the loading of a particulate washingtank according to the present invention.

[0036]FIG. 2 is an enlarged elevation view of the balance of themonitoring unit employed in the system according to the presentinvention.

[0037]FIG. 3 is a schematic diagram of the various units employed in thehydraulic system according to the present invention.

[0038]FIG. 4 is a schematic diagram of the electrical elements employedin the system according to the present invention.

[0039]FIG. 5 is an elevational view of the lower end of the washing tankshowing the pair of hinges required for adjusting the inclination of thewashing tank.

[0040] Similar reference characters denote corresponding featuresconsistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0041] The present invention in FIGS. 1A, 1B, 2, and 3 is directed to aweight sensing system 10 for a log washer tank for adjusting theinclination of the tank in response to changes in the load ofparticulate material to be washed in the tank 12, shown partially inFIG. 1A. In FIGS. 1A and 1B, an electrical control box 14 is connectedto a pressure module 18 and to a high/low pressure sensor switch 30(FIG. 3). A boxed divider/combiner valve 20 is depicted in FIGS. 2 and 3having a plurality of hydraulic lines 22 connected to a hydraulic pumpand reservoir, and also to a pair of hydraulic cylinders 24 for raisingand lowering the tank. The hydraulic cylinders 24 are mounted below theupper end of the water tank and on opposite sides of the tank, only oneof the cylinders 24 being shown in FIG. 1A, the opposite side beingsymmetrical. As shown, the cylinders are preferably mounted with thetank bearing on the bottom end of the cylinder and the ram or piston rodresting on a fixed support.

[0042] As shown in FIG. 3, the divider/combiner valve 20 controls thehydraulic pressure actuating the two hydraulic cylinders 24 equally. Apredetermined high elevation limit and a low elevation limit in terms ofthe ram or piston rod travel is set by conventional mechanical leverswhich trigger high-low electrical switches 26. A hydraulic line from thedivider/combiner valve 20 communicates with a pressure gauge 28 and ahigh/low pressure sensor switch 30. The hydraulic line divides to a highpressure circuit 32 and a low pressure circuit 34. The high pressurecircuit 32 includes in sequence a one-way check valve 36 to prevent backflow from the cylinders 24 to the pumps 54 but which will open onexcessive pressure from the pump 54 to raise the cylinders 24, anormally closed hydraulic valve/solenoid element 38, and a high pressurerelief valve 40 which dumps off excessive hydraulic pressure throughline 42 to the low pressure circuit 34. The low pressure circuit 34consists of a normally closed hydraulic valve/solenoid 44, a needlevalve 46, a hydraulic fluid return line 48 which also receives fluidfrom the hydraulic line 42 to flow to the hydraulic oil supply tank 50.The needle valve 46 regulates how quickly the tank 12 is lowered. Whenhydraulic fluid is required for raising the hydraulic cylinders 24 bysignal from the high/low pressure sensor switch 30, an electric ordiesel motor 52 is energized by the electrical control box 14 to startand run an auxiliary hydraulic pump 54 to increase the hydraulicpressure to the pair of hydraulic cylinders 24 to elevate the washertank 12 to the predetermined degree of inclination.

[0043] As the load in the upper end of the washer tank increases, theadditional weight bearing on the bottom ends of hydraulic cylinders 24increases hydraulic fluid pressure in the system. When the hydraulicpressure exceeds a predetermined high pressure limit, the high/lowpressure sensor switch triggers the solenoid connected to hydraulicvalve 44 in the return lines 34 to open the valve 44 to release fluidfrom the cylinders 24, thereby lowering the tank until the hydraulicpressure does not exceed the high pressure limit or until the maximumlow level limit of ram or piston rod travel is reached. This actionincreases production flow through the log washer tank, but adequatecleaning is maintained by the greater quantity of particulate matterproviding the scrubbing action in the tank. When the hydraulic pressureis under a predetermined high pressure limit, the high/low pressuresensor switch triggers the solenoid connected to hydraulic valve 38 toopen the valve 38 to increase fluid flow into the cylinders 24, therebyraising the tank until the hydraulic pressure exceeds the low pressurelimit or until the maximum high level limit of ram or piston rod travelis reached. The action slows production flow through the log washertank, but increases the scrubbing time to compensate for the reducedvolume of particulate matter to maintain adequate cleaning of theparticulate matter.

[0044] Alternatively, the high/low pressure sensor 30 for measuringvariations in hydraulic pressure under differing loads can be replacedby a sensor which measures the variations in amperage required to drivethe logs at constant speed under differing load conditions.

[0045]FIG. 4 shows a partial schematic of the electrical control systemfor raising and lowering the hydraulic cylinders 24. The circuitincludes a power switch 56 for the hydraulic pump 54. A pair of switches58 and 60 (or alternatively a double pole, double throw switch) areincluded for switching between automatic and manual activation of thehydraulic pump 54 and raising and lowering of the hydraulic cylinders24. Another switch 62 is provided for selecting between raising andlowering the cylinders 24 during manual operation. During automaticoperation, operation of the circuitry is controlled by the high/lowpressure switch 30, which activates the raise cylinder circuitry 64 whenthe RPS switch 30 a is closed and the LPS switch 30 b is open, as shownin FIG. 4, or activates the lower cylinder circuitry 66 when the RPSswitch 30 a is open and the LPS switch 30 b is closed, or activatesneither the raise cylinder circuitry 64 nor the lower cylinder circuitrywhen both the RPS switch 30 a and LPS switch 30 b are open. The state ofthe RPS 30 a and LPS 30 b switches is dependent on the load in the tankas sensed by the high/low pressure switch 30.

[0046] The raise cylinder circuitry 64 includes appropriate solenoidsand relays for raising the cylinders 24, including the solenoidcontrolled hydraulic valve 38, pressure gauge 28, a bypass valvesolenoid 68, a time delay relay including coil 70 and contacts 72, alatching relay including coil 74 and contacts 76, upper cylinder travellimit switch 26 a, and a driver relay including coil 78 and contacts 80.The lower cylinder circuitry 66 includes appropriate solenoids andrelays for lowering the cylinders 24, including the solenoid controlledhydraulic valve 44, pressure gauge 28, lower cylinder travel limitswitch 26 b, and latch relay release coil 82.

[0047] As noted above, FIG. 5 illustrates the pair of hinges 100 mountedat the lower end of the tank 12 which are required to enable theadjustment in the inclination angle of the tank 12 in order to maximizethe cleaning action of the wash tank 12 operation. The bearings 102supporting the lower ends of the two log screws are also shown.

[0048] Thus, an effective system for automatically or manually raisingand lowering the inclination angle of the tank 12 has been shown formaximizing effective scrubbing of the solids being washed.

[0049] It is to be understood that the present invention is not limitedto the embodiment described above, but encompasses any and allembodiments within the scope of the following claims.

I claim:
 1. A load sensing system for a log washer for washing aggregatematerials, comprising: a log washer tank having a pivotally mountedlower end and having an upper end; a pair of hydraulic cylinders, eachhydraulic cylinder having a cylinder base depending from the upper endof the log washer tank and a piston rod attached to a fixed groundsupport, the hydraulic cylinders being disposed on opposite sides of thelog washer tank; a combiner/divider valve connected to the pair ofhydraulic cylinders; a hydraulic pump and a hydraulic fluid reservoirconnected to the combiner divider valve for pumping fluid to andreceiving fluid from the combiner/divider valve for extending andretracting the piston rods; a high/low pressure sensor switch disposedbetween said hydraulic pump and said combiner/divider valve, the sensorswitch having a first state when hydraulic pressure exceeds a highpressure limit, a second state when hydraulic pressure falls below a lowpressure limit, and a third state when hydraulic pressure is between thehigh pressure and low pressure limits; raising means for extending thepiston rods of the pair of hydraulic cylinders when hydraulic pressurefalls below the low pressure limit; and lowering means for retractingthe piston rods of the pair of hydraulic cylinders when hydraulicpressure is above the high pressure limit; whereby the log washer tankis raised and lowered to an angle of incline with only the aggregatematerial load for promoting efficient washing in response to changes inweight of the load.
 2. The load sensing system according to claim 1,further comprising a check valve disposed between said hydraulic pumpand said combiner/divider valve for preventing back flow of hydraulicfluid through said hydraulic pump.
 3. The load sensing system accordingto claim 1, further comprising a high pressure relief valve disposedbetween said hydraulic pump and said combiner/divider valve fordiverting hydraulic fluid to said hydraulic reservoir when hydraulicpressure produced by said hydraulic pump exceeds a high pressure limit.4. The load sensing system according to claim 1, wherein said raisingmeans comprises a hydraulic valve disposed between said hydraulic pumpand said combiner/divider valve, the hydraulic valve having a solenoidconnected to said high/low pressure sensor for opening and closing thehydraulic valve.
 5. The load sensing system according to claim 1,wherein said lowering means comprises a hydraulic valve disposed betweensaid hydraulic reservoir and said combiner/divider valve, the hydraulicvalve having a solenoid connected to said high/low pressure sensor foropening and closing the hydraulic valve.
 6. The load sensing systemaccording to claim 1, further comprising a needle valve disposed betweensaid combiner/divider valve and said hydraulic reservoir for regulatingthe flow rate of hydraulic fluid to said hydraulic reservoir.